This invention relates to an improvement in non-contact measurement systems and methods, and more particularly, but not by way of limitation, to a method and system for determining the contour of an electrically conductive surface by a means of an electrical probe means which is brought to a predetermined position near but not touching said surface in a plurality of positions.
It has been known in the past to provide electrical systems to provide spacing between a movable member and a fixed member. In U.S. Pat. No. 3,217,204 a welding torch assembly is maintained at a fixed distance relative to a metallic workpiece by means of an electrical system that controls a driving motor coupled to the torch assembly. As the torch assembly is moved along a seam to be welded, the electrical system thus maintains the torch assembly at an optimum constant distance from the workpiece in order to achieve a good weld.
In U.S. Pat. No. 2,870,427 a device is disclosed for detecting and indicating the proximity of objects. This device utilizes an object sensing antenna which causes alteration of the output or a high frequency oscillator, and this causes production of an electrical signal which may be translated into a signal perceptible to the user.
In U.S. Pat. No. 4,107,603 an electromagnetic apparatus is disclosed for detecting propeller shaft bearing wear. As the propeller shaft rotates, an electromagnetic sensor provides a signal corresponding to the displacement of the shaft transverse to its longitudinal axis and thereby indicative of the wear of the bearing supporting the propeller shaft.
As can be seen, heretofore to the present invention, while there have been various apparatus provided for the sensing of distance of a movable member from a fixed member or to maintain such distance constant there has not been seen a non-contact measurement system and process for determining the contour of an electrically conductive surface. As an example of an application of the present invention, it is necessary at times to determine the contour of a concave electrically conductive object as a matter of determining its final contour or of determining its contour in an interim step of manufacture. Since such objects may be very fragile, contact measuring systems are not satisfactory and the instant invention provides a highly accurate means of determining the contour of an electrically conductive surface without altering the surface thereof.